Asubstance decays so that the amount a of the substance left after t years is given by:
a = a 0 · (0.9) t ,
where a 0 is the original amount of the substance. what is the half-life (the amount of time that it takes to decay to half the original amount) of this substance rounded to the nearest tenth of a year?

If you draw a card with a value of three or less from a standard deck of cards, i will pay you $43. if not, you pay me $11. (aces are considered the highest card in the deck.) step 1 of 2 : find the expected value of the proposition. round your answer to two decimal places. losses must be expressed as negative values.